Effectiveness of improvement of benefit of the electric power selling charges and electricity charges using battery storage system and heat pump water heater for high penetration PV

Recently home energy management system (HEMS) has been spread due to increase in awareness of save energy after Great East Japan Earthquake. HEMS consists of photovoltaic power system (PV), battery energy storage system (BESS) and heat pump water heater (HPWH), etc. Residential PV implementation rate has been increasing due to feed in tariff from 2009. So there is a danger of output suppression loss due to voltage increase on a distribution line due to reverse power flow from each residential PV. So we try to study how to reduce output suppression loss using BESS and HPWH optimally. One of the main purpose to implement BESS and HPWH is for economy using the difference in electricity charges between during nighttime and daytime. So in this research, we optimize how to operate BESS and HPWH to improve the benefit of the electric power selling charges and electricity charges considering reduction of output suppression loss and the difference in electricity charges between during nighttime and daytime.